Method of and apparatus for annealing materials



Dec. 16, 1930. c s. KINGSLEY METHOD OF AND APPARATUS ,////////fi@ Q E r T r g M m V N Dec. 16, 1930. B. KINGS LEY 1,785,264

METHOD OF AND APPARATUS FOR ANNEALING MATERIALS Filed March a, 1927 a sheet -sheet} 3 HIS. ATTORNEYS I Patented Dec. 16,

,U ITE srarasfPAT N orrlca owns rlxmesmr, oncLam'roN, rmmsrnvanm, assrenoa "r" mssrssrrrx enass conramr, acoaroaarronor NEW roar u HETH O DOI' ANDAI PABATUS I03 ANNEALING HATEBIALB The presentiinvention relates" to methods of and ap aratus for annealing materials scribed and with speci nealing ofsheet glass."

- a paratus Figurelis application to the continuous anin substances according to my new methods,

of" my invention.

a. structure 2 having bottom,'side walls and I top as shown in section in'Figurel with a igu re2is a sectional view'o'f the appa-- ratus of Fi re land taken alo gline aa r thereof wit the enclosing side wall brok away to show the arrangement interior partsmore clearly, and

l igures 3, 4, and 6,show-modifiediforrns In the drawings the apparatus comprises '5 stein o'f-live rolls 3, 3, which pass through the side walls 2 and find su port and contact with ower actuating-,mec anism on either sideo the. structure, outside of the sidewalls 2 all of which is foundin the apparatusas pi'acticed in the art at the presenttime. In the continuous annealing of a continuousformed sheet of "glass I find it of advantage to "adjustably suspend an inside 'hori- I I zontal flat or curved curtain or cover 4 'of blocks of clay or other suitable-material as shown in cross section in Figures 1 and 4, and in longitudinal section, in "part, in Figure 2, alon the length of the annealing apparatus an in the space "C between the rolls 3, 3, andthe top wall "of the 'a 'iparatus' zontal curtain 4 a suitable mechanical applr ances are provided outside and above the enclosing structure 2 'as indicated in Figure '1 comprlsing supporting screw stem hangers 5, 5, gearnuts I6, 6, operating worms'fl and 1027 send in 173,878.

In operating annealing apparatus of the ind cated type wlthout the special suspended hOIlZOIltflI curtain it has been found difiil eult'and often impossible to control the air currents throughout the large cross section of the enclosed space and inequalities intem: peratures of the sheet take i lace, causing resu ts, an it is t e purpose of my invention to so protect andconfine thecontinuous sheet of 'glassshown at 9, being carried forward on the live rolls 3, that the required control of temperatures is possible foraproperannealing and cooling, of the sheet to insure a properly annealed and flat sheet, and thus prevent splits and breaks in the sheet due to,

improperg cooling. r a p a a a y In he operation of my, annealin equipment the vertical adjustment of the hanging horizontal curtain is essential as it is desirable to haveit supported'close to the sheet of warping, s littin ;and,genera objectionable glass so that the vertical sides of thecurtain 4 may closein over the ends of the livc rolls f ,and prevent air currents from circulating under the curtainat this point, the eurtainfin Jthe loweredposition as shown ,on the drawings forming a shallowflatlor curved arch in'which the tops of the rolls operate "and through which theyjcarry the sheet of glass andproviding additional m'ass along the-sensitive edge 'where otherwise coolingljtakes place morerapidly than in the center of; the

sheet and thus I promote and obtain an 'equalize d'cooling of thesheet as'a whole. 7

'While' a function of'the horizontal curtain 1s to stop a1r v currents causing lnequal tiesin temperature iI lf the zone through which the glass sheet is passing an important factor is that the mass or material com 'ri'sin the horizontal curtain absorbs the ra iated eat from the sheet of glass and because of itsgrea ter mass willnot sufi'er local or zone changes in v p "itstemperaturewdue to thecircul'ating air For theraising and lowering of this horicurrents in the larger chamber C caused by radiations from the enclosing surfaces of chamber 0, and the heat of the larger mass 1 as furnished by the horizontal curtain t rovides a uniform' temperature across the s eat at any articular point or cross section and'a gradua change in temperature longitudinally of chamber G along the length'thereof, as is known in the art.

' len The utilizationof a vertically adjustable horizontal curtain 4 is of value in the continuous process of making sheet glass in two ways, i. e.: When the operation of making continuous sheet glass begins there is often a rough, lumpy surface, also elevated ed es and rojecting points so that it will be esirab e to give a ditional clearance above the rolls 8 for the a'ssagebf the head end of the sheet. As the desired initial temperautres of the zones making up the total lon itudinal dimension of chamber 0 will have been obtained before the entry of the hot sheet of glass, it is possible to have the horizontal curtain 4 in an elevated osition for any desired clearances above t e rolls 3 as an interval of time elapses between the entry of the sheet and the critical disturbance of desired temperature conditions initially established in which time the horizontal curtain 4 may be lowered to its operating osition.

The second advantage in aving a movable horizontal curtain 4 is that as the cooler zones in chamber G are reached by the advancing sheet of glass additional cooling effect may be obtained by increasing the distance of the horizontal curtain from the sheet.

, To be able to establish varyin operating distances between the horizonta curtain 4 and the sheet ofmoving glass or rolls 3 will also be a desirable feature when various thicknesses of sheet latent heat of t e sheet to be dissipated varies and the rate of travel of the sheet throu h the annealing chamber changes and a flex'ib e control of the temperature in the annealing chamber is desired.

The horizontal openings between sections of the curtain 4 are closed b tile 6 or other suitable material to shut 0 air currents at these points, and the various sections along the length of the curtainmay beadjusted in any desirable variation of height with relation to each other and to the rolls 3, 3, and

the curtain may be made of two longitudinal members 4 and 4a as shown in Figure 3,1eavingl w an an open space along the length thereof said opening may be left open, or close with tile, as shown at 7 in said Figu either wholly or partially along the length thereof to meet the needs of seryice, as desired.

In some instances it may he 'desired'to vary the. distance of the various sections along the gth of the curtain with relation to the rolls 8, 3, and the construction shown in'Fi ure 5 will, 'rmit of obtainin .pra'cticall t e widest-1n ations desired, ere, the si es of 1glass are to be annealed, as the the curtain 4 are shown as separate members 4?), 4b, suspended in fixed position and to have sliding engagement with the edges of the curtain 4.

In other instances, it may be desired to protect only the edges of the glass sheet from too rapid cooling and the curtain 4 can then be constructed and mounted as shown in Figure 6, to secure equalized cooling of the sheet as a whole.

As a further description of the principle in the application of a sus ended horizontal curtain to the annealin 0 continuous sheet lass a comparison of t e physical action w ich takes place in the annealing of a continuous thin glass sheet and the annealing of a continuous thick sheet of glass may be used. In the annealin of thin sheet glass the latent heat of the sheet is easily dissipated and being of less mass, with a lesser total latent heat, it is both easier to add or subtract heat to or from itat local points or areas or over its entire area than 1s possible in the case of a thick sheet which naturally carries a greater total latent heat because of its eater mass.

I This susceptibilit of the thin 5 act of glass of glass a greater range of temperature variations is possible becauseof the less sensitive nature of thick sheet due to its greater mass and consequent higher totallatent heat contained, which in practice does not show the same tendency to warp, check orbreak in the process of annealing.

This invention takes advanta e of this principle by addin to the heat retaining mass of the thin sheet, t e heat retaining mass of the horizontal suspended curtain, which having been brou ht up to local temperatures established in t e chamber 0 before the entry of the sheet of glass serves both as a rewrvoir and an absorber of heat and a less susceptible mass from which heat may be taken without the local differences sufi'ered b small mass as contained in a t in sheet of glass. I V

While the advantages of the horizontal suspended curtain are not so pronounced in its application to the annealing'l'of heavy'or thick continuous sheet glass, st its sluggish or slow response to quick or Iocalcha es in temperature in chamber C will aid n the more satisfactory and perfect annealing of the sheet and is egually desirable.

An advantage -0 great in rtance in this a body of invention is that the latent eat of the continuous sheet of hot lass is conserved in the horizontalsuspend curtain and will reduce or added to the chamberG if not under some conditions makin the adding of additional heat unnecessary rereby working a desirable and beneficial savingin I claim: e

1. The method of annealing a continuously formed sheet of glass, comprising advancing the sheet of glass through an annealing chamber. of fixed cross section, and controlling the rate of cooling of the sheet of glass as it passes through. said chamber by interposing 7 between the upper surface of the sheet and the upper wall of said chamber a heat absorbing and heat retaining element without restricting the cross sectional area of the chamber.

i 2. The method of annealing a continuously the cost of annealing.

' formed sheet of glass, comprising advancing tion comprising an open ended treating chamthe sheet of glass through an annealin chamber of fixed cross section, and control ing the rate of cooling of said sheet through any cross sectional area of the chamber by interposing heat absorbing and retaining element intermediate the sheet and the top wall of the chamber, said element serving to eliminate objectionable air currents around and about said sheet and limiting the cross sectional area only by its own cross sectional area.

3. In an apparatus for annealing a continuously formed sheet of glass, the combinaber of fixed crosssection, means for conveying a sheet of glass throughsaid chamber, and means for equalizing'thedistribution of heat transfer in a'sheet ofglass at any cross ing-a sheet ofsection thereof, said means comprising a curtain of heat absorbmg and retaining material disposed above the sheet of glass and I said curtain area of said within said treating chamber, restricting the cross sectional chamber only by its owncross section.

4. In an apparatus for annealing a continuously formed sheet of glass, the combinetion comprising an open ended treating chamber of fixed cross section, means for conveylass through said chamber, and a heat absor ing and heat retaining curtain disposed immediately above the sheet of glass and away from the walls of said open ended chamber. e

5. In an ap aratus for annealing a'contin uously forme sheet of glass, the combination comprising an open ended treating chamber of fixed cross section, means for consaid chamber,

currents at the edges of the sheet of glass and immediately above its upper surface, said means comprising a curtain of heat absorbing and retaining material spaced from the upper wall of said open ended chamber.

6. In an apparatus for annealing a continuously formedsheet of comprising an open on ed treating chamber of fixed cross section, means for conveying a nature.

CHARLES B. KINGSLEY.

Ill,

lass,'the combination 

